Chemistry Reference
In-Depth Information
181, obtained by a last-step phosgenation with phosgene of protected (as a Schiff
base) aryl aminocarbonyl compounds 180, have recently been described [113].
O
NH
N
Cl
COCl
2
Me
Me
R
R
N
N
180
181
Diferrocenyl amines (which are unexpectedly di
cult to derivatize), useful for the
preparation of novel diferrocenylamino compounds, including nitrenium salts,
amino radicals, transition metal amides, and carbamato ligands, are transformed
in a multistep process, with phosgene, into the corresponding carbamoyl chlorides
[114].
An interesting silver ion mediated lactam formation between the carbamoyl
chloride and enecarbamate in 183 has been reported [115]. The starting substrate,
183, a useful intermediate in the stereocontrolled total synthesis of (
þ
)-Gelsemine,
was prepared with phosgene.
O
O
EtO
EtO
NH
NH
CH
2
OMe
CH
2
OMe
O
O
Me
Me
COCl
2
HN
N
ClOC
OAc
OAc
182
183
O
EtO
NH
HO
O
CH
2
OMe
O
Me-N
OAc
184
Various short-chain dialkylamines (R
1
Me, Et, R
2
Me, Et, iPr) 185 react with
diphosgene in dioxane at 55-60
C [116] or hexachloroacetone [117] to give the
corresponding carbamoyl chlorides 186.
¼
¼
